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Dilute sulfuric acid contains water. The ions present in this mixture are H⁺ and OH^- (from the water) and H⁺ and SO₄^2- from the sulfuric acid. The H⁺ ions are attracted to the cathode and the two negative ions are attracted to the anode but it is the OH^- ion which loses electrons.

• H⁺ ions are attracted to the cathode, gain electrons and form hydrogen gas
• OH^- ions are attracted to the anode, lose electrons and form oxygen gas and water

Higher tier

At the cathode: 2H⁺ + 2e^- → H₂

At the anode: 4OH^- → O₂ + 2H₂O + 4e^-

Colourless gases are produced at each electrode. The volume of hydrogen produced at the cathode is twice the volume of oxygen produced at the anode.